SUBSCRIBE
BIOS 105 Chapter 14
1. cannot account by itself for the increase in species diversity over time:
Answer The main focus of Charles Darwin's studies was on the gradual process of adaptation within populations. In other words, microevolution occurs by means of natural selection.Although critical to evolution this form of change, .
2. speciation:
Answer New branches form on the tree of life through the process of .
3. changes in the gene pool of a population from one generation to the next:
Answer Microevolution is .
4. are male and female, but cannot interbreed:
Answer Two animals are considered members of different biological species if they .
- This is the most convenient way of identifying species, and it is one of the few ways to
identify fossil or asexual species.:
Answer Why is the morphological species concept still used to define and describe species?
- Observe them together under natural conditions to see if they interbreed to produce fertile
offspring.:
Answer Lake Victoria is home to a group of related fishes known as cichlids. Hundreds of forms are present, differing slightly in their color patterns, habitat use, and feeding behavior.What is the best method for scientists to determine conclusively whether the fish are members of a population that has a lot of variation or whether they are members of entirely different species?
- a group of populations whose members can interbreed in nature and pro- duce fertile
offspring:
Answer According to the biological species concept, a species is .
8. morphological:
Answer The species concept is practical for identification of unfa- miliar species and has 1 / 3
SUBSCRIBE
been used to describe most of the 1.8 million known species on Earth.
9. oaks and other sexually reproducing, extant (currently living) trees:
Answer For which of the following groups would the biological definition of species be useful?
10. morphological:
Answer The species concept is the most applicable to classifying species from the fossil record.
11. biological ... different species:
When a horse and a donkey mate, they produce infertile hybrids called mules. According to the species concept, horses and donkeys are .
12. Two dragonfly species regularly mate, but their gametes are incompatible.:
Answer The following options are all reproductive barriers. Which one is an example of a prezygotic barrier in which the two different species do mate?
- One species is diurnal (day active) and mates at high noon; the other is nocturnal (night
active) and mates at midnight.:
Answer Which of these is an example of temporal isolation?
- The two species evolve independently because they do not exchange genes.
Reproductive barriers keep them from successfully interbreeding.-:
Answer Each biological species is genetically isolated from other species. Why do the species evolve independently?
15. over the past 10,000 years, no speciation occurred in these flies:
Answer Imagine that part of a population of flies is blown from the California coast to an offshore island. The island flies have no contact with the mainland flies for 10,000 years. Then an earthquake rearranges the landscape and the island is rejoined to the mainland. The former island flies can now mingle freely with the mainland flies. If attempts at mating between flies from the two groups are successful and the resulting offspring grow up strong and healthy and have offspring of their own, you could conclude that .
16. prezygotic ... behavioral isolation:
- / 3
SUBSCRIBE
Answer Three species of frogs—Lithobates pipi- ens, Lithobates clamitans, and Lithobates sylvatica—all mate in the same ponds, but they pair off correctly because they have different calls. This is a specific example of a barrier, called .
17. temporal isolation:
Answer Two species of water lilies in the same pond do not inter- breed because one blooms at night and the other during the day. The reproductive barrier between them is an example of .
18. Two fruit flies of different species produce viable but sterile offspring.:
Answer Which of the following is an example of a postzygotic reproductive barrier?
- The hybrid offspring of two species of jimsonweeds always die before reproducing.:
Answer Which is a postzygotic reproductive barrier?
- Many insects have intricate "lock and key" mechanisms that prevent the male genitalia
of one species from engaging with the female genitalia of a different species.:
Answer Which of the following is an example of mechanical isolation?
- Pollen is regularly exchanged between flowers of two groups of plants, but a mutual
incompatibility exists so that sperm do not fertilize eggs from the "wrong" group.:
Answer Which of the following is an example of a prezygotic barrier?
22. temporal isolation:
Answer Two species of clams inhabit the same marine habitat along the Atlantic coast. One releases gametes into the water in early spring, and the second species releases gametes into the water in late summer. Which type of reproductive barrier is at work between these species?
23. geographic isolation:
Answer What is the first step in allopatric speciation?
- the allopatric population is small and is isolated from the parent population by a formidable
barrier to dispersal:
Answer Speciation is likely to occur between a parent population and a population that has become allopatric if .
- / 3